If I visited myself four years ago from the future, and said that Donald Trump would win in 2016, I doubt I'd react any differently than Doc Brown.
The Future repeats itself too, apparently!
Present me: Then tell me, who wins in 2016?
Future me: Donald Trump!
PM: Donald Trump? The reality show star? Ha!
PM: Then who's vice president? Chris Christie? I suppose Marla Maples is first lady! And Newt Gingrich is Secretary of State!
FM: Wait! Oh, you're almost right! Different wife, but you're close.
PM: I've had enough practical jokes for one evening...